RECOVERY-STRESS STATE AND SELECTED HORMONAL MARKERS OF TRAINING STRESS

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DISSERTATIONES KINESIOLOGIAE UNIVERSITATIS TARTUENSIS 8

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DISSERTATIONES KINESIOLOGIAE UNIVERSITATIS TARTUENSIS 8

THE PERCEIVED

RECOVERY-STRESS STATE AND SELECTED HORMONAL MARKERS OF TRAINING STRESS

IN HIGHLY TRAINED MALE ROWERS

JAREK MÄESTU

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Faculty of Exercise and Sport Sciences, Universtiy of Tartu, Tartu, Estonia Dissertation is accepted for the commencement of the Degree of Doctor of Philosophy (in Exercise and Sport Sciences) on October 8, 2004, by the Faculty Council of the Faculty of Exercise and Sport Sciences, University of Tartu Opponents: Prof. Dr. Jürgen Steinacker, PhD, University of Ulm, Germany

Prof. Dr. Jüri Allik, PhD, Tartu Ülikool, Eesti Commencement: December 9, 2004

Autoriõigus Jarek Mäestu, 2004 Tartu Ülikooli Kirjastus

www.tyk.ut.ee Tellimus nr. 554

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LIST OF ORIGINAL ARTICLES

PAPER I:

Jürimäe J., Mäestu J., Purge P., Jürimäe T., Sööt T. (2002) Relations among heavy training stress, mood state, and performance for male junior rowers.

Perceptual and Motor Skills, 95: 520–526.

PAPER II:

Mäestu J., Jürimäe J., Jürimäe T. (2003) Psychological and biochemical markers of heavy training stress in highly trained male rowers. Medicina Dello Sport, 56: 95–101.

PAPER III:

Mäestu J., Jürimäe J., Jürimäe T. (2003) Hormonal reactions during heavy training stress and following tapering in highly trained male rowers.

Hormone and Metabolic Research, 35: 109–113.

PAPER IV:

Mäestu J., Jürimäe J., Jürimäe T. Hormonal response to maximal rowing before and after heavy increase in training volume in highly trained male rowers. Journal of Sports Medicine and Physical Fitness (In Press).

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1. INTRODUCTION

In the world of sports, athletes and coaches push themselves harder and harder in order to achieve the best result during the competitions. However, by increasing either the frequency, duration or intensity of training, they risk creating excessive fatigue that may lead to functional impairment, which has been described as staleness or burnout (Hooper et al., 1995). The aim of sport training is to accustome the human body through different training loads and competitions, at the same time minimizing the risk of illness and fatigue in the period shortly before the competition. Thus, athlete’s body must accustome with training loads that are intense enough to displace the homeostasis of an athlete. Once the adaptation to a certain training load has occurred, a greater load must be applied to get further improvement. Stressful high intensity training periods are necessary to obtain high performance in sports (Steinacker et al., 1998). A problem for a coach is also that athletes respond different to same training loads. A load that is too high for one athlete, may have no training effect at all to the other. It is evident, however, that underestimation or overestimation of the performance level, trainability and insufficent recovery will lead to: 1) inappropriate training response of the athlete; or 2) overreaching and in the long run staleness, burnout syndrome or overtraining (Bruin, 1994;

Kuipers & Keizer, 1988; Lehmann et al., 1993).

Further increases in performance can be reached by increasing intensity and duration of exercise (Bannister et al., 1997; Steinacker, 1993). For rowers, it has been demonstrated that daily rowed kilometers are positively related to rowing performance (Hagerman & Staron, 1983; Steinacker, 1993). This makes the training process complicated, because increasing training volume and mono- toneus training will increase the risk of overtraining.

The recovery of athletes from the fatigue of intense training stress has had far less attention in previous studies, although tapering (a gradual reduction of training load) has been used to allow the athlete to recover from intense training and thus optimize training process and performance prior competitions. To date, rest (physical inactivity) is the best known treatment for athletes who have reached an undesirable state because of prolonged training (Lehmann et al., 1993; Kuipers & Keizer, 1988; Raglin, 1993). Only few studies have investigated the markers for monitoring recovery processes of athletes during the taper (Hooper et al., 1995; Simsch et al., 2002; Steinacker et al., 2000).

However, these studies have used different metabolical and psychological parameters and have used different types of training.

Evaluation of the overall state of an athlete and appointing appropriate training load without leading the athlete to ovrtraining syndrome has been among the most complicated tasks in the field of coaching sciences and sports medicine. Several parameters (e.g., clinical findings, hormonal, psychological, metabolic) have been studied (Barron et al., 1985; Lehmann et al., 1997;

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Simsch et al., 2002; Snegovskaya & Viru, 1993; Steinacker et al., 1999, 2000;

Urhausen et al., 1987; Vervoorn et al., 1991). To date, these parameters have either shown inconsistent responses, or where trends have appeared, there are too few studies to make definite conclusions. Therefore, the aim of current dissertation is to monitor simultaneously the stress and recovery processes of highly trained male rowers and to investigate the response of different hormones and athletes’ subjective ratings of stress and recovery during a period of heavy training stress in highly trained male rowers.

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2. REVIEW OF LITERATURE 2.1. Characteristics of rowing performance

Rowing is primarily a strength-endurance type of sport. The typical rowing competition takes place on a 2000 metre course and lasts, depending on a boat type and weather conditions 5.5–7.0 minutes. During a rowing race muscle contraction is relatively slow and about 32–38 duty cycles per minute are used.

Maximal power per stroke may reach as high as 1200 W and average power per race is about 450–550 W (Steinacker, 1993). During competition, a rower depends mainly on his/her aerobic metabolism because energy stores and glycolysis are limited to cover the energy demand only for approximately 1.5–

2.0 minutes (Steinacker, 1993). Aerobic power can be defined as the maximal oxygen consumption as estimated during a performance that lasts two to 10 minutes (Jensen, 1994). Aerobic and anaerobic energy contributions on a 2000 metre rowing race in different studies are presented in Table 1. According to Roth et al. (1983), the energy of the 2000 metre race was provided 67% aero- bically and 33% anaerobically, 21% alactic and 12% lactic. While Secher et al.

(1982) found that the aerobic energy contribution may be up to 86%.

Table 1. Mean contribution of aerobic and anaerobic energy during extensive rowing in different studies using elite heavyweight male rowers.

Studies Number of

subjects Aerobic

energy % Anaerobic energy % Russell et al. (1998)

Hagerman et al. (1978) Hartmann (1987)

Mickelson & Hagerman (1982) Roth et al. (1983)

Secher et al. (1982) Messonnier et al. (1997)

19 310

17 25 10 7 13

84 70 82 72 67 70–86

86

16 30 18 28 33 14–30

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Many factors affect physical performance during rowing. Power depends on aerobic and anaerobic energy supplies balanced by efficiency or technique (Jen- sen, 1994). Efficiency is expressed as the relationship between energy expendi- ture and boat velocity. Efficiency depends on the technical skill of the rower and varies as much as from 16 to 21% even during ergometer and tank rowing (Bunk & Leso, 1993; Lakomy et al., 1993). Differences in efficiency between rowers and non-rowers have been demonstrated, while no differences were observed between elite lightweights selected for World Championships team compared with those who did not make the team (Lakomy et al., 1993). This

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indicates that efficiency on an ergometer is only a rough estimate of technique in the boat (Jensen, 1994).

Testing an athlete is an attempt to evaluate his/her sport-specific performance. The easiest way of doing this is to measure the shortest time needed to cover a particular rowing distance. However, it is rather complicated, because external factors like wind, currents, and temperature may influence the result.

Furthermore, a need may exist to evaluate the individual contribution to a boat including as many as eight rowers (Jensen, 1994). Rowing ergometers are commonly used to measure individual performance parameters in rowers and training changes. Although rowing an ergometer does not require the same skills as on-water rowing, it has been observed that the ergometer simulates the biomechanical and metabolic demands of on-water rowing (Lamb, 1989). Thus, it should also be taken into consideration that rowing ergometers are valuable tools in testing, but they should be used in care when developing endurance during the preparation period, because they may affect seriously the technique of on-water rowing.

Many researchers (Table 2) have found performance predictive parameters for rowers to predict 2000 metre rowing ergometer performance (Cosgrove et al., 1999; Ingham et al., 2002; Jürimäe et al., 1999, 2000; Perkins & Pivarnik, 2003; Riechman et al., 2002; Russell et al., 1998; Womack et al., 1996) and two of them (Jürimäe et al., 1999, 2000) also developed performance predictive parameters for 2000 metre single scull distance. These studies used rowers of different levels, classification (scullers, sweep rowers), sexes and that may be the reason why each study had different equations of performance predictive parameters. Howerver, all these studies reported either maximal oxygen consumption (VO2max in l · min^–1) or maximal aerobic power (Pmax in W) to be an important parameter in predicting performance on a 2000 metre rowing ergometer distance. For example, Ingham et al. (2002) and Womack et al. (1996) found that VO2max, Pmax, oxygen consumption at 4 mmol · l^–1 blood lactate level were highly correlated with 2000 metre rowing ergometer performance.

Contrary to this, Riechman et al. (2002) found that 2000 metre rowing ergometer performance is best characterized by mean power of 30 second all-out ergometer test (i.e. anaerobic lactic power) and VO2max. Similar results were obtained by Jürimäe et al. (2000), who reported Pmax and mean power of 40 second work (i.e. anaerobic lactic power) to be the best predictive parameters of 2000 metre rowing ergometer performance.

Jürimäe et al. (2000) compared ergometer rowing with on-water rowing and found that from different anthropometric characteristics only muscle mass was correlated with 2000 metre single scull distance, while almost every anthropometric variable was related to 2000 metre rowing ergometer distance. In support to this, Russell et al. (1998) reported that anthropometrical parameters alone predicted the 2000 metre rowing ergometer distance best compared to metabolic parameters and combination of both categories. Thus, care should be taken when interpreting the rowing ergometer results to predict on-water rowing

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performance, because anthropometric variables may have too big influence of the result. In smaller and lighter rowers on-water rowing speed is usually compensated by higher physiological parameters, which is clearly indicated by the fact that in international regattas some lightweight rowers may easily compete with their heavier peers.

Table 2. Performance predictive parameters for rowers on 2000 metre ergometer distance in different studies.

Classification Parameters Comments Study

13 male college level

rowers – VO2max

– lactate 5 minutes after 2000 ergometer all-out

May be due to homogenous group, rowing economy was not found to be an important predictor to rowing success

Cosgrove et al., 1999

41 international level male and female rowers including lightweights

– Power at VO2max

– VO2max at 4 mmol · l^–1 – Power at

4 mmol · l^–1 – Pmax

May be not specific enough, becose both male and female and also lightweights were used

Ingham et al., 2002

19 elite schoolboys – Height – Body mass – Skinfolds

Sweep rowers were used, who are known to be taller and heavier than scullers

Russell et al., 1998 12 international

female rowers

– Power of 30sec all-out

– VO2max

– Fatigue

A 30 sec Wingate test, with fatigue measure was developed to predict 2000 metre rowing performance

Riechman et al., 2002

10 male college level

rowers – VO2max

– Peak velocity – Velocity at

4 mmol · l^–1 – VO2max at

4 mmol · l^–1

The rest period during the incremental test could have too big influence on the VO2max value.

Womack et al., 1996

10 male national level

rowers – Pamax

– La 350W

– CSA thigh – Height – Muscle mass

Compares on-water and rowing ergometer performance parameters

Jürimäe et al., 2000

VO2max – maximal oxygen consumption; Pmax – maximal aerobic power; La350W – blood lactate concentration at 350W power; CSA thigh – the cross-sectional area of a thigh

The accurate analysis and assessment of various components of performance within the training context is an important process for coaches and sport scientists to include as an integral aspect of the training and competition programme of a rower. Determinants of competitive success include various psychological attributes such as self-motivation (Raglin et al., 1990), technical

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skills including balance (Mester et al., 1982), coordination with other crew members (Wing & Woodburn, 1995), in addition to the physiological characteristics of muscular endurance, aerobic power, anaerobic power and strength characteristics (Shephard, 1998). Hereby, a good testing battery for a rower needs several parameters to determinate his/her performance and to make selection process more effective. A key aspect to bear in mind with physiological tests is the extent to which it is actually correlated with performance (Smith, 2002).

Changes in performance capacity can be analysed during all-out rowing tests in a rowing boat over various distances or on the rowing ergometers. Maximum performance (P_max) during a standardized test (2, 6 and 7 minute all-out, 500, 2000, 2500 and 6000 metre all-out, tests on anaerobic threshold, etc.) can be used for evaluation of the exercise capacity (Gullstrand, 1996; Hagerman, 2000;

Hagerman & Staron, 1978; Jensen, 1994; Jürimäe et al., 1999, 2000; Mahler et al., 1984; Messonnier et al., 1997; Peltonen & Rusko, 1993; Smith et al., 2000;

Snegovskaya & Viru, 1993; Vermulst et al., 1991; Womack et al., 1996).

However, Steinacker et al. (1998) argued that P_max is subject to motivation of the rower tested and thus may not be sensitive enough to monitor a complete rowing season and raised a question of more reliable test programmes such as fast ramp tests, because they may fit into training program more easily.

However, in a study of Smith et al. (2000) no changes were found in 500 metre rowing ergometer time nor power after 3 weeks of overload training with 33%

increase in the frequency and 30% increase in training volume and the following tapering week in international male and female rowers. It may be explained by the fact that anaerobic energy production may have too big influence on the test results and it is well known that in successful rowers anaerobic capacity trainings are less than 10% of the whole training time.

Endurance capacity is an important result of training and regeneration (Mickelson & Hagerman, 1982; Steinaker et al., 1998). Higher performance at a fixed or individual lactate threshold means higher maximum performance, but there is a wide scattering of individual data of rowers. In successful rowers, the 4 mmol · l^–1 lactate threshold is in the range of 75 to 85% of their Pmax (Secher, 1993; Steinacker, 1993). It should be taken into account that different testing protocols and different types of ergometers used may contribute different levels of 4 mmol · l^–1 blood lactate levels. For example, Lormes et al. (1993) found higher lactate levels for a given heart rate on the Gjessing than on the Concept II rowing ergometer, a possible reason of power losses in the transmission system of the Gjessing rowing ergometer. Maximal lactate values decrease with higher lactate threshold, as an indicator of increased endurance capacity (Steinacker, 1993). However, using fixed or individual lactate threshold values as guidelines for training intensity must be viewed with caution, because they do not mirror exactly the blood lactate steady-state for rowers (Bourgois &

Vrijens, 1998). Lactate threshold and maximum lactate values are also influenced by preceding exercise and muscle glycogen stores (Steinacker, 1993).

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Thus, all variables before testing the athlete must be standardized to avoid difficulties in interpretation of the test results. In a glycogen deficient state, maximum lactate and performance are depressed and lactate threshold virtually increased, but in the state of overreaching or overtraining without glycogen deficit, maximum lactate and performance capacity and lactate threshold are decreased or lactate threshold unchanged (Lehmann et al., 1992; Steinacker et al., 1998, 1999).

Nowadays, the blood lactate response to exercise is commonly accepted as a tool for performance assessment and training prescription (Steinacker, 1993;

Tokmakidis et al., 1998). The blood lactate response has been investigated thoroughly and described using variety of terms and definitions (Bishop et al., 1998; Tokmakidis et al., 1998). The anaerobic threshold has been one of the most commonly used terms for describing the blood lactate response. Anaerobic threshold can be defined as the workload that can be performed by the oxidative metabolism and at which blood lactate production and release are balanced during continuous exercise (Bishop et al., 1998; Kindermann et al., 1979;

Tokmakidis et al., 1998).

To determine anaerobic threshold, numerous concepts and definitions have been published in the last decades. A number of methods are based on the observation that blood lactate levels change suddenly at some critical work rate and thus reflect a threshold phenomenon (Brooks, 1985). For example, some authors consider the anaerobic threshold to be the work rate at which the lactate concentration first begins to increase above the resting level (Yoshida et al., 1987), whereas others have suggested an increase of 1.0 mmol · l^–1 above baseline during incremental exercise (Coyle et al., 1983). To overcome the disadvantage of visual, subjective determination of anaerobic threshold, lactate parameters may also be identified by using various curve fitting procedures such as log-log transformation (LTLOG) (Beaver et al., 1985), the DMAX method (Cheng et al., 1992), or a modified DMAX method (DMOD) (Bishop et al., 1998).

Other investigations have proposed a fixed lactate level to define and detect anaerobic threshold. For example, values of 2.0 mmol · l^–1 (LaFontaine et al., 1981), 3.0 mmol · l^–1 (Föhrenbach et al., 1987) and 4.0 mmol · l^–1 (Kindermann et al., 1979) have been used. Although a number of competing models exist to fit blood lactate concentration data during incremental exercise, there has been little comparison between different concepts in rowers. However, different anaerobic threshold concepts (Table 3) and their relationships to rowing performance were studied by Jürimäe et al. (2001b). The authors concludeded that LTLOG represented the rowing ergometer performance time best.

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Table 3. Blood lactate values recorded during the incremental rowing ergometer test in male rowers (n = 21) (modified from Jürimäe et al., 2001b).

Parameter LT

(mmol · l^–1) LT1

(mmol · l^–1) LTLOG

(mmol · l^–1) LTD

(mmol · l^–1) LTMOD

(mmol · l^–1) Mean±SD 2.5±0.6 3.2±0.7 3.7±0.8 4.5±1.0 5.6±0.9 LT — the power output preceding the first increase in blood lactate concentration above the resting level during an incremental exercise test; LT1 — the power output at which blood lactate increases by 1.0 mmol · l^–1 or more; LTLOG — the power output at which blood lactate concentration begins to increase when the log (lactate) is plotted against the log (power output); LTD — the lactate threshold calculated by the Dmax method;

LTMOD — a modified LTD method.

Steinacker (1993) and Wolf and Roth (1987) have reported that the submaximal aerobic capacity measured as the power which elicits a blood lactate level of 4.0 mmol · l^–1 is the most predictive parameter of competition performance in trained rowers, especially in small boats such as singles and doubles, but some authors have questioned the physiological significance of a fixed blood lactate value of 4.0 mmol · l^–1, which does not take into account the inividual kinetics of the lactate concentration curve (Coyle, 1995; Stegman et al., 1981). More- over, a power at blood lactate level of 4.0 mmol · l^–1 has not been reported to represent a steady state workload in rowing (Beneke, 1995; Bourgois & Vrijens, 1998). Using 21 male rowers, Jürimäe et al. (2001b) found anaerobic threshold value to be 3.7 mmol · l^–1 (see, Table 3), which is lower than suggested 4 mmol · l^–1 value and may therefore be better to select training intensities without accumulation of blood lactate. Moreover, a deflection point using LTLOG

method was very easily detected, allowing more accuracy for each athlete.

Thus, LTLOG value, which detects the anaerobic threshold with less subjectivity, may be a more appropriate measure of training modality in rowing, however, it must be still confirmed in future studies.

This is in contrast with the results of previous studies (Bishop et al., 1998;

Tanaka & Matsura, 1984; Yoshida et al., 1987), who reported different anaerobic threshold concepts to represent steady-state in different endurance events. The results of these studies indicate that there is not one blood lactate parameter that best predicts competition performance in all endurance events.

For endurance events of different intensity and duration, different blood lactate parameters may provide a simple method of estimating a pace that does not result in premature fatigue (Bishop et al., 1998).

In conclusion, aerobic and anaerobic capacities both seem to be an important parameters in competitive rowing despite the level, sex, body mass, etc., and both components are worth testing to better understand the performance of a rower. For anaerobic threshold level, a method when the power output at which blood lactate concentration begins to increase when the log (lactate) is plotted against the log (power output) may represent the threshold inensity better than

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commonly used 4 mmol · l^–1 blood lactate concentration. It should also be taken into consideration that a 2000 metre rowing ergometer performance is suitable for rowers, who compete in big boats like fours and/or eights. When performance of rowers in small boats is measured, a 2500 metre ergometer distance appears to more closely reflect the metabolic effort of on-water rowing on singles and doubles (Jensen, 1994; Jürimäe et al., 2000).

2.2. Characteristics of rowing training

During a rowing race (approximately 5.5 to 7.0 minutes, average power per stroke 450–550W), anaerobic alactic and lactic as well as aerobic capacities are stressed to their maximum (Steinacker, 1993). Therefore, the training of successful rowers has to be built up on the focus of aerobic training with the proper relation with strength and anaerobic training.

Endurance training (training at blood lactate concentration of 2–4 mmol · l^–1) is the mainstay of success in rowing (Howald, 1988; Mahler et al., 1984;

Secher, 1983,1993; Steinacker, 1988, 1993). Training of successful athletes is characterized by extensive as well as intensive endurance training with approximately 70–80% of the time spent on the water (Jensen et al., 1993; Marx, 1988;

Steinacker, 1988). Intense endurance training above the anaerobic threshold may be important for improvement of VO_2max during the competitive season, but should not amount to more than 10% of the training volume (Steinacker, 1993). Over the year, the percentage of specific rowing training on the water is 52–55% for the 18 year old, 55–60% for the 21 year old, and up to 65% for the older athlete. Strength training is in the range 20% at the 18 year old and 16% at the adult athlete, and general athletic training is in the range from 26–23%, respectively (Altenburg, 1997). It is important to increase specific rowing training with increased training experience (Steinacker et al., 1998).

The preparation period of rowers starts usually in October, where the main goal of training is to build up a base through aerobic extensive endurance training (90% of the total training time) (Nielsen et al., 1993). It appears that during the preparation period, rowers should deemphasize strength training at low velocities and emphazise power development at higher velocities (i.e. train more specifically for the types and velocities of movements used in the rowing technique and at speeds necessary to mimic the competitive pace) (Hagerman, 2000). The main period for developing strength-endurance is from January to March (Nielsen et al., 1993). The competitive period starts in March and culmi- nates for elite rowers in late August or in early September with World Rowing Championships. During competitive period, the aerobic training is still the most important (about 70% of total training). About 25% of the training during the competitive season is aerobic-anaerobic (blood lactate concentration 4–8 mmol · l^–1) training and the rest is purely anaerobic (blood lactate concentration

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above 8 mmol · l^–1) training (Nielsen et al., 1993). Steinacker et al. (1999) investigated the time course of rowing velocity and ergometer results of a coxed eight during the training camp before Junior World Championships 1995. This preparatory training programme had a duration of approximately 4 weeks: 2 weeks high-intensity / high-volume training, tapering 1 week and in the last week special preparation for the finals. The slowest boat speed of the 2000 metre distance was observed during the high-volume / high-intensity, and the fastest boat speed was observed at the time trial 4 after the tapering period and at the World Championships.

In rowing, for stuying training effects the problem is the complexity of the goals of training because different capacities (aerobic, anaerobic, power, strength, tactical skills) have to be improved (Steinacker et al., 1998). This causes timing problems, because several capacities cannot be developed at the same time. For example, endurance and sprint training are not appropriate to develop in the same training session. For rowers, one of the most important task is the maintenance of strength gains while training to enhance aerobic endurance simultaneusly (Bell et al., 1993), as strength training is one physical performance factor of a complete annual training programme (Hagerman &

Staron, 1983; Secher, 1993). Research has shown that a sequence of strength training prior to endurance training may be preferred for off-season for rowing (Bell et al., 1988,1991). Bell et al. (1993) found significant strength gains with a training frequency of three times per week for 10 weeks and were maintained for at least six weeks where the main goal was to develop aerobic endurance and strength training was conducted only once or twice per week (Bell et al., 1993). Whether strength gains can be maintained beyond six weeks while performing endurance training is not known (Bell et al., 1993) and needs further research.

Most rowers use also unspecific and cross training to increase training tolerance and to avoid overtraining. During cross training, different muscle groups are recruited, which may allow partial recovery of other muscle groups and therefore, the advantages of cross training seem to be “peripheral” effects, enhancing or maintaining strength in power training and “central” effects by decreasing monotony of trainings (Steinacker et al., 1998). However, it has to be stated that in international level the relation of specific and unspecific training has to be in the range of 70% and 30%, respectively (Altenburg, 1997;

Nielsen et al., 1993).

In conclusion, endurance training is the main type of training in rowing, which has to be in proper relation with strength and speed training. Over the career the percentage of specific rowing training must increase and reache 65 to 70% in elite rowers.

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2.3. Psychological monitoring of training in rowing

In addition to clinical findings, the level of psychologically-related stress and recovery seems to reflect well the state of athletes (Kellmann & Kallus, 1999;

Steinacker et al., 2000). Furthermore, mood state, e.g., motivation and striving for success, seems to be closely related to actual performance (Kellmann &

Kallus, 1999; Morgan et al., 1987; Secher, 1993). Shephard & Shek (1994) argued that psychological testing provides both easier and more effective methods for detecting the overtraining syndrome than methods dependent on various physiological or immunulogical markers. To date, most common psychometric instruments used were the one item Borg ratio scale (Borg, 1998), which was developed to subjectively measure the intensity of the exercise; the Profile of Mood States (POMS) (McNair et al., 1992), which measures only current stress; and Recovery-Stress-Questionnaire for Athletes (RESTQ-Sport) (Kellmann & Kallus, 2001), which allowes measuring both subjectively perceived stress and recovery. It has to be considered that the Borg ratio scale, RESTQ-Sport and the POMS are not direct measures of physiological states of the organism, these instruments reflect the subjective representation of these states (Kellmann & Kallus, 1999).

During a training programme, mood state did not differ between those who adhered to the programme and the dropouts; however, those who remained in training had higher self-motivaton (Secher, 1993). During training, mood state increased, but suprisingly remained elevated in those who did not make the team, but decreased in those who were successful (Secher, 1993). Marriot &

Lamb (1996) found a highly consistent relationship between Borg ratio-scale perceptions of exertion on a rowing ergometer and heart rate. When the rating of perceived exertion was used as a means of producing an appropriate training heart rate, it was satisfactory but only as the higher intensities of effort (ratings 15 and above) (Marriot & Lamb, 1996). Urhausen et al. (1998) found significantly higher ratings of subjective exertion in overtrained endurance athletes.

However, the one-item construction of the Borg ratio scale cannot assess different aspects of recovery and stress (Kellmann, 2002).Moreover, it is diffi- cult to interprete what causes the change of the scale after standardized exercise, and therefore, proper intervention is complicated. Thus, the Borg ratio-scale is not suitable for monitoring training in highly trained athletes (Kellmann, 2002).

There is convincing evidence that athletes can be distinguished on the basis of psychological skills and emotional competencies (Smith et al., 2002). The POMS was initially developed as an economical method of identifying and assessing transient, fluctuating affective state (McNair, 1992). The POMS consists of 65 items and it yields a global measure of mood, consisting of Tension, Depression, Anger, Vigour, Confusion and Fatigue. An overall score is computed by summarizing the five negative mood states and subtracting the positive mood state (Vigor). The POMS has also been used to measure mood

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state of rowers (Kellmann & Kallus, 1999), swimmers (Morgan et al., 1987) and runners (Verde et al., 1992). Verde et al. (1992) concluded that resting heart rate, sleep patterns and hormonal changes do not provide a useful early warning that the peak of the performance has been passed, but the POMS score showed a consistent pattern of loss of Vigour and Fatigue during heavy training of three weeks in runners. Morgan et al. (1987) measured mood states of swimmers throughout the season. At the beginning, the swimmers exhibited the “iceberg profile,” an indicator of a mentally healthy state. In high load phase, mood disturbances increased and a profile reflected poor mental health. After reducing the intensity, the swimmers demonstrated the original “iceberg profile” again. A dose-response relation between mood disturbances and training intensity is prevalent (Raglin, 1993),

However, Kelmann (2002) argued that if we assume that the POMS can identify overtrained athletes at an early stage, the question then arises as to what kind of intervention should take place. Because the items of the POMS are in adjective form (e.g., Confusion, Vigor, Anger), it does not provide information of the cause of the mood (Kellmann, 2002). Furthermore, Berger & Motl (2000) noted the disadvantage that the POMS was initially developed for use with clinical populations in order to have an economical method of identifying and assessing transient, fluctuating states. In addition, five of the of the six scales of the POMS measure the negative mood characteristics of Tension, Anger, Fatigue, Depression and Confusion and a decrease in a negative mood state may not necessarily indicate mood benefits (Berger & Motl, 2000). Therefore, the POMS only vaguely reflects recovery processes and does not lead to the application of appropriate recovery strategies (Kellmann, 2002).

Restricting the analysis to the stress dimension alone is insufficient, especially in high performance areas, since the management of training intensity and volume is tightly linked to outstanding performance (Steinacker et al., 2000). A psychometrically based instrument to assess the recovery-stress state is the RESTQ-Sport. The recovery-stress state indicates the extent to which persons are physically and/or mentally stressed, whether or not they are capable of using individual strategies for recovery as well as which strategies are used (Kellmann

& Günther, 2000). This questionnaire was created to get distinct answers to the question “How are You?“ (Kellmann, 2002) and addresses physical, subjective, behavioral, and social aspects using a self-report approach (Kellmann & Kallus, 1999). The theory behind the questionnaire is that an accretion of stress in everyday life, coupled with weak recovery potential, will cause a variation of the psychophysical general state (Kellmann, 2002).

Several studies have showed that POMS scales Depression, Anger and Fatigue are negatively correlated with recovery associated scales of RESTQ- Sport, at the same time Vigor is positevily correlated (Kellmann et al., 2001;

Kellmann & Günther, 2000) and vice versa, a positive relationship exists between the stress related scales of RESTQ-Sport and Depression, Anger and Fatigue, while Vigor appears to be negatively correlated with stress scales.

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Longitudinal studies in German and American athletes participating in different sports have shown that the RESTQ-Sport can sensitively monitor stress and recovery processes in training camps and throughout the season (Kallus &

Kellmann, 2000; Kellmann & Günther, 2000; Kellmann & Kallus, 1999;

Steinacker et al., 2000). Moreover, a dose-response relationship was demonstrated between training volume (daily rowed kilometers) and the somatic components of stress and recovery in rowers (Kellmann & Günther, 2000;

Steinacker et al., 2000).

Using 11 elite rowers during their preparation for the 1996 Atlanta Olympics, Kellmann & Günther (2000) found that the alteration of extensive endurance training was well reflected in psychological measures. High duration was indicated by elevated levels of stress and simultaneuos lowered levels of recovery. Moreover, the scales Somatic Complaints, Lack of Energy, Fitness/

Injury, and Fitness/Being in Shape described the dose-response relationship with the training load. However, the different trends in the RESTQ-Sport scales may be explained by the different time courses of hormones and corresponding scales (Steinacker et al., 1999). For example, Somatic Complaints were highest with the highest training load and elevated cortisol concentrations as well as creatine kinase activity.

In conclusion, through utilization of the RESTQ-Sport coaches and athletes can be informed of the importance of daily activities and how these activities are related to recovery-stress state of athlete’s compared to the frequently used one-item Borg scale or POMS, which in general measures the stress related behaviour and thus, could not be sufficient in high performance areas. Previous studies (Kellmann & Günther, 2000; Simsch et al., 2002; Steinacker et al., 1999, 2000) utilizing RESTQ-Sport could suggest that it is appropriate to measure recovery-stress state changes during rowing training in highly trained male athletes.

2.4. Selected blood biochemical indicies of training monitoring in rowing

In the world of training and coaching, different biochemical indicies in blood are used to prevent and to diagnose overtraining syndrome as an unwanted result of athlete’s training regimen. The acute responses in the endocrine system during physical exercise may be related to the intensity and duration of the specific exercise as well as to the physical condition of the athletes (Häkkinen et al., 1989; Remes et al., 1985). Evaluation of serum hormones during prolonged physical activity and/or training has also received considerable attention due to its implications for general adaptive mechanisms and for physical conditioning (Häkkinen et al., 1989). However, to date, there is still no valid diagnostic tools that would help us to prevent overtraining. Different hormonal responses were

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often proposed for monitoring overreaching and overtraining situations and also for recovery period (Häkkinen et al., 1989; Kuipers & Keizer, 1998; Lehmann et al., 1991,1993; Simsch et al., 2002; Snegovskaya & Viru, 1993; Steinacker et al., 1999, 2000; Urhausen et al., 1987, 1998). Endogenous hormones are essen- tially involved in exercise-induced acute or chronic adaptions and influence the regeneration phase through the modulation of anabolic and catabolic processes after exercise (Urhausen et al., 1995). Hormonal mechanisms most assuredly help mediate both short-term homeostatic control and long-term cellular adaptations to any type of stress are imposed on man. For example, cortisol and growth hormone exert an essential role both in short-term (control on utilization of energy substrates, mobilization of protein resources) and prolonged stable (amplification of the translation process, supply of protein synthesis by

“building materials”) adaptation to exercises (Viru, 1985).

Since cortisol levels in humans show a circadian rhythm, with low levels in the late evening and high levels in the early morning, it has to be taken into account when collecting the hormone sampling (Fry et al., 1991; Hackney et al., 1988).

Testosterone shows no specific pattern, but fluctuations due to nervous stimuli in response to temperature, psychological events and amount of light in the day, have been reported (Hackney et al., 1988; Hoogeveen & Zonderland, 1996).

Numerous investigations have studied the effects of different kind of prolonged physical stress has on the hormones of hypothalamus-pituitary-adreno- cortical axis (Häkkinen et al., 1989, Simsch et al., 2002; Steinacker et al., 2000;

Vervoorn et al., 1991). Prolonged heavy endurance training has found to cause the increase and decrease in the morning basal levels of cortisol and testosterone, respectively (Vervoorn et al., 1991). While resting levels of cortisol have reported to be unchanged (Mackinnon et al., 1997) or decrease (Flynn et al., 1994) after endurance training in male athletes.

The exercise induced cortisol increase depends on the duration and intensity of physical exercise (Snegovskaya & Viru, 1993). A significant increase in the blood cortisol level usually requires a duration of exercise of more than 20 minutes with at least 60% of the VO2max and is primarily the consequence of a higher secretion rate. In previously trained sportsmen, the further improvement of performance capacity is connected with an increased functional capacity of endocrine systems (Snegovskaya & Viru, 1993). During the post exercise phase, cortisol decreases rapidly and, within hours, reaches an initial value (Urhausen et al., 1995).

In rowers, the further improvement of performance capacity was associated with increased growth hormone and cortisol levels and elite rowers have a higher values of cortisol and growth hormone compared to national and medium performance level (Snegovskaya & Viru, 1993). These results are somewhat controversial to Steinacker et al. (1993) study, who reported higher cortisol values for rowers who were not selected to National Junior Team of Germany, indicating higher catabolic activity. At an early stage during the training camp before World Junior Championships 1996 in German Junior Team, when the

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training load was highest, basal cortisol levels increased by 18% and decreased slightly afterwards (Steinacker et al., 1999). Elevated basal cortisol levels are often seen as a normal stress response to high-intensity training (Steinacker et al., 1993,1998). For example, the increase in cortisol level was found in junior rowers after anaerobic training during the last days before the blood sampling (Steinacker et al., 1993). There were no changes in plasma cortisol and testosterone concentration after two hours of rowing at the intensity of 75% of 4 mmol · l^–1 anaerobic threshold (Jürimäe et al., 2001a). Steinacker et al. (2000) found human growth hormone increase from baseline (0.45 ng.ml^–1) to 10% in high load training phase (training load approximately 180 minutes per day for two weeks), but a decrease of 30% during the tapering phase where training volume was reduced for about 30%, but the intensity was maintained.

Adlercreutz et al. (1986) and Härkonen et al. (1984) stated that a condition of overstrain might exist in an athlete if at least one of the two following criteria are fulfilled: 1) free testosterone/cortisol ratio lover than 0.35 x 10^–3; and/or 2) a decrease in free testosterone/cortisol ratio of 30% or more. During a rowing season, no significant relationships were found between free testosterone/

cortisol ratio and rowing ergometer performance parameters in highly trained male rowers (Vervoorn et al., 1991). However, a decrease in free testosterone/

cortisol ratio was observed after the training camp (range 4–40%), but these changes were not significantly related to performance parameters (Vervoorn et al., 1991). The authors concluded that the criterion of a decrease in the free testosterone/cortisol ratio of 30% or more nor the free testosterone/cortisol ratio lower than 0.35 x 10^–3 cannot be regarded as a first sign of overtraining (Vervoorn et al., 1991). Therefore, the free testosterone/cortisol ratio seems to be more useful as an indicator for a status of insufficient time to recover from training, in particular when such a decrease is caused by a decrease in plasma free testosterone concentration (Vervoorn et al., 1991).

Catecholamines stimulate cardiovascular and metabolic reactions and indicate physical and psychological stress (Galbo, 1983; Kindermann et al., 1982; Lehmann et al., 1985). All-out rowing is usually associated with extre- mely high plasma catecholamine levels — 19 nmol · l^–1 and 74 nmol · l^–1 for adrenaline and noradrenaline, respectively (Holmquist et al., 1986; Jensen et al., 1984). Higher noradrenaline concentrations were noted during endurance training at similar heart rate on the Gjessing rowing ergometer compared to rowing in the boat, but adrenaline values were not statistically different (Urhausen et al., 1993). It was concluded that, because of the higher sympatho- adrenergic activation when exercising on the ergometer, the intensity of ergometer rowing should be set carefully (Urhausen et al., 1993).

The plasma leptin level is identified as an adipocyte-derived hormone and its receptor has highlighted the regulation of appetite, thermogenesis and metabolism (Friedman & Halaas, 1998). Leptin is considered to be one of the physiological signals designed to prolong survival in hazardous situations like strenous exercise or starvation, mainly by reducing basal metabolic rate, increasing food seeking

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behaviour, increasing the secretion of glycocorticoids and decreasing reproductive function (Flier, 1998). However, it has become evident that leptin does not act only as an “adipostatic hormone” (Steinacker et al., 2003). It has also been shown that exogenous leptin is a potent stimulus of growth hormone secretion (Tannenbaum et al., 1998). Studies have shown that endurance exercise sessions decrease the plasma leptin concentration after 48 hours, in association with a preceding decrease in insulin (Essig et al., 2000), while short-term exhaustive exercise has no immediate or delayed effect on circulating leptin concentration (Hickey et al., 1996). In the literature, the responses of plasma leptin to exercise are controversial. It has been suggested that fasting plasma leptin is not regulated in a dose-response manner in competitive male swimmers (Noland et al., 2001), while it has shown to be decreased in heavy training in highly trained rowers during high load training and increased when training load was decreased (Simsch et al., 2002). These controversial results could be explained by the differences in physical stress as the training regimen of the swimmers in Noland et al. (2001) study was intensive high load interval training, while in Simsch et al. (2002) investigation was high intensity strength training.

Furthermore, Simsch et al. (2002) demonstrated a positive relationship between leptin levels and rowing performance. These results are controversial to Petibois et al. (2002), who argued that plasma leptin is not sensitive to an increase in training volume for trained individuals. There is the hypothesis that leptin expression in the adipocyte is related to energy flux and triglyceride loss (Considine, 1997). Accordingly, there is not a consensus about the effect of different training regimen on plasma leptin concentrations in humans.

Recently, Urhausen & Kindermann (2002) suggested that instead of resting hormone concentrations, maximal exercise-induced hormonal responses during and after a period of training overload should be studied to assess the adaptivity of the athletes. The elevation of hormone levels after rowing exercises performed at the maximal possible rate may be an overall expression of the dependance of hormone changes on the exercise intensity (Snegovskaya &

Viru, 1993). This means that there should be a wide reserve to increase the hormone responses to exercise. Only a sufficient performance capacity has to be achieved to evoke a correspondingly large rise in hormone concentrations (Snegovskaya & Viru, 1993).

Despite the episodic character of growth hormone secretion, its response during exercise is characterized by a continuous increase of blood level during the exercise (Viru & Viru, 2001). Growth hormone response to submaximal exercises has found to decrease or disappear, as a result of training (Buckler, 1973; Sutton et al., 1969). There is also a possibility that fatigue may modulate growth hormone response (Viru & Viru, 2001). For example, Urhausen et al. (1998) demonstrated a decrease in ecercise induced rise of growth hormone, while Lehmann et al. (1992) found no change in resting nor exercise induced values of growth hormone. In the state of overreaching and overtraining, an intra-

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individually decreased maximum rise of cortisol and insulin has also been found after a standardized exhaustive exercise test (Urhausen & Kindermann, 2002).

For several years, serum creatine kinase activity has been measured as a parameter of muscular stress in training associated studies. A particularly important consideration relating to the use and interpretation of creatine kinase values in the sports sector is the dependence of this parameter on nature of the stress (Hartmann & Mester, 2000). Creatine kinase activity reflects training intensity and muscular strain only at the beginning of a training phase, decreasing creatine kinase activity and suggesting muscular adaptation to training (Steinacker, 1993; Steinacker et al., 1998; Urhausen et al., 1987). Morning levels of creatine kinase activity represent mainly its release during the previous day and are also influenced by creatine kinase clearance (50–80% per day) (Steinacker et al., 1993). Steinacker et al. (1993) found higher creatine kinase values in the junior rowers who were not selected to the national team, indicating higher muscular strain despite their lower physical power.

In summary, it seems that at present a lack of valid biochemical markers of training stress exist in rowing. However, the study of Simsch et al. (2002) has proved the decrease of leptin in high load training phases due to hypothalamic dysfunction and, therefore, it could be a marker of training stress in rowers. It could also be suggested that the maximal exercise-induced changes in biochemical values may represent the more sensitive markers of training and possible overreaching in athletes.

2.5. Studies on monitoring training in rowing

In the literature, there are not very many longitudinal studies that deal with training monitoring of rowers. Some of them are summarized in Table 4. Most of them are three to five weeks of duration — one microcycle. Only few of them (Cosgrove et al., 1999; Snegovskaya & Viru, 1993; Vervoorn et al., 1991, Vermulst et al., 1991) are longer than one microcycle. However, these longer studies tend to monitor only one specific pattern or the time between two different testing battery is too long. There is also a lack of studies which deal with rowing performance and resistance training. Bell et al. (1988, 1989, 1991, 1993) have investigated high velocity resistance training (HVRT) relation to rowing training. However, they have compared HVRT to anaerobic power and reported no significant changes in anaerobic power after different training programs (Bell et al., 1989) High intensive resistance training was also used in the study of Simsch et al. (2002) and the stagnation in performance of incremental ergometer test was detected, but after endurance training the performance increased significantly. It is known that building up the strength-endurance capacity during off-season is one part of rowers’ winter training program.

The impact of low-velocity resistance training (frequency, intensity, etc.) at least during off-season on rowing performance needs some further research.

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ble 4. Studies involving training monitoring in rowers. ferenceSubPerDesignPerformanceBlood parametersMood StateConclusions voorn et , 19916 M9 monTesting int. 5 w. 5’at AT4 , Pmax 2’ all-outPmax almost unchanged. AT4↑ 12% if load↑ 110%. Heavy int. AT4↓ 8%

C, FT, FTCR almost unchanged Int training-FTCR↓ 40%, taper-FTCR↑ 60%

5 weeks of training does not induce a change in La dynamics, when comparing AT4 with perceding test in highly trained rowers. FTCR may be a parameter of early hormonal overstrain with interpretation with training logs. Decrease of 30% is not regarded as overtraining. einacker et , 199335 M26 daysPmax-incremental test, AT4 and 6 min all-out 16 days Aer-119.6’, Thr- 6.5’, An-2.3. 10days Aer-91.2’,Thr – 6.5’, An-3.2’.

AT4 (W)↑ 4.6%Load 128 min/day FTCR↑ 24%, T↑ 20%, Urea↑ 20.8%, CK↑ 25%. Load 90 min/day C↑ 23.5%, T↑ 23.2%, FTCR↑ 7.9%, Urea↓ 10.3%, CK↓ 27%

AT4 (W) 4.1% and Pmax 3.4% higher in national team rowers than non selected rowers. msch et al.,6 M6 w3 w RT 16.6 h/w (55% RT) 3 w ET 14.3 h/w Pmax-incremental test

AT4 tend to↓ in RT and tend to↑ in ET. VO2 tend to↑. Pmax↑ in ET.

L↓ 27%, C↓ 30%, TSH↓ 23% in RT. L tend to↑, C tend to↑, TSH↑ 22% in ET.

The ↓ of TSH and the peripheral thy- roid hormones could be attributed to lower hypothalamus levels and is reated to ↓ L levels. L – possible director of monitoring training. aya u, 199335 M20 monPmax 7’all-out in group A Feb, June, Oct. In group B March, Jan, June.

Pmax↑ 14.6% HR tend to increasePost exercise levels of C and GH↑Improvements in performance capacity was associated with increased GH and C. rmulst et al.,6 F9 monTesting int. 5 weeks. 5’at AT4 , Pmax 2’ all-outAT4↑if vol↑ 150% (aerobic training, submax intensity). AT4↓ if vol↨ (70–75% aerobic, emphase on intensive distance training. Pmax-slight 5–10% increase

Not specifiedAT4 is a useful parameter for measuring aerobic capacity of the female rowers. Pmax does not seem to give a valid estimation of the actual maximal power in female rowers. , 200010 M5 wVol 56% in 2 w and 40% for 2 w (90% ext rowing) Pmax-incremental test 2000 m rowing on 8+ RESTQ

Pmax↑ 2.7%, Lamax↑ 3.3%, LaAT4↑ 8%In overload Hct↕, C↕, DHEAS↕, FT ↕, ALD↑, LU↓10%, FSH↓11% , GH↑10%, Ins↓ 17%. In taper Hct↕, C, DHEAS, FT↑10%, ALD↑, FSH↑ 9%, GH↓30%, Ins↑37%.

Som Comp, Gen Str, Som Rel, Self Reg, Fitness reveal a significant cubic trend of the dependant variables Overreaching was indicated by decreases in P and increases in stress and deterioration in recovery values in RESTQ. This was also indicated by suppression of central and peripheral stress hormones.

RECOVERY-STRESS STATE AND SELECTED HORMONAL MARKERS OF TRAINING STRESS

THE PERCEIVED

RECOVERY-STRESS STATE AND SELECTED HORMONAL MARKERS OF TRAINING STRESS

IN HIGHLY TRAINED MALE ROWERS

JAREK MÄESTU

CONTENTS

LIST OF ORIGINAL ARTICLES

1. INTRODUCTION

2. REVIEW OF LITERATURE 2.1. Characteristics of rowing performance

2.2. Characteristics of rowing training

2.3. Psychological monitoring of training in rowing

2.4. Selected blood biochemical indicies of training monitoring in rowing

2.5. Studies on monitoring training in rowing